Our summer visitor arrived on a perfect lake day, when the sky was clear blue, a gentle breeze brushed the shore, and the water was warm enough to go in without a moment’s hesitation. It had been several years since she had been to the lake, and she told us she looked forward to hearing the call of a loon. The words had barely left her mouth when a loon called, and we watched the look on her face turn from one of hope to one of sheer delight. The loon called again, a slow mournful wail. It probably was calling to its mate, but from the look of joy on our summer visitor’s face it was as if the loon were calling to her, welcoming her back to the lake.

The loon’s wail is a soft, drawn out sound that starts low, rises in the middle, and slowly descends again. It is a contact call between loons saying, “I’m here — where are you?” Another call we often hear is the tremolo, which some folks mistake for laughter, but which is actually an alarm call. If the tremolo rises in pitch or increases in frequency it signals that the loon is becoming increasingly anxious. Sometimes, we hear haunting tremolo duets by neighboring loons who are marking off territorial boundaries, or by a mated pair defending their space from interlopers. Loons also use this call when people get too close to their chicks, or to warn a boat to stay out of an area where the loon is fishing. Just as we don’t like to be interrupted in the middle of a meal, a loon who is diving frequently is fishing and does not want to be disturbed. Sometimes, kayakers and other boaters float peacefully near loons, especially if they have a chick. They think that as long as they remain quiet they are not bothering the loon, but if a loon shows any reaction such as moving away, calling, or rising up in the water showing its white breast, it feels threatened. When that happens it’s time to go away.

Loons fascinate us, and it seems we never tire of seeing these handsome birds. Unlike most other water birds, loons are designed for diving and fishing. With wings pressed against the body, and neck stretched out, the loon propels itself underwater like a torpedo, with both feet moving together. Their bones are heavier than those of other birds, and their legs and feet are far back on the body for underwater swimming, a design that makes it almost impossible for loons to stand or walk on land. They go on land only to mate and incubate eggs. In the air, loons are strong fliers, but their high ratio of body weight to wing size makes it difficult for them to take off, so they must flap across the water for as much as a quarter of a mile to get airborne.

Unlike other water birds, who can nest in a variety of places and who may produce 10 offspring in each brood, loons have very specific requirements for nest sites, and if they are able to find a proper site may lay only one or two eggs a year. The loon chicks usually hatch by early July. About an hour after hatching they are able to swim, and they go into the water with their parents. For the first few weeks the little chick will often climb onto the parent’s back, or tuck under its wing, to get warm and to be safe from snapping turtles, eagles, and other predators. Looking like nothing more than a small bit of black fluff on the water, the young chick can be nearly invisible, and can be killed easily by a motorboat. It can not swim fast, fly, or dive to escape danger, so it’s up to the parents to try to protect it by warning people away, and it’s up to us to read their signals. Fortunately, loons are excellent parents. They will carefully guard their chick, teach it how to survive, and feed it for three months, until it can get all its food by itself and can finally fly. Before the lake freezes the loons will leave and fly to the ocean for the winter. The chick will stay on the ocean for several years, until it grows the black-and-white adult plumage and is ready to return to a lake and start a family.

The loon on our lake called its low mournful wail, and we had to agree with our summer visitor. It felt as if the loon were calling to each one of us.

Jean Preis resides in Bridgton.